The use of flashlights and related illumination equipment to provide underwater lighting is well known. With the inclusion of a portable power supply, such as a battery pack, a diver is able to carry with him a safe, stable illumination source to provide visibility in the dark and murky depths. Conventional underwater lighting has long utilized incandescent bulbs as a light source. Such bulbs can be driven directly by a battery pack and thus provide minimal difficulties in being installed in a watertight housing.
Incandescent bulbs, however, have shortcomings. The light normally generated is of a yellow, rather than white, character, and is often of relatively poor intensity. In addition, such bulbs are inefficient light generators. To combat such deficiencies, miniature high-intensity discharge (HID) bulbs are replacing incandescent bulbs for use in underwater flashlights. The use of such HID devices, however, is not without its own shortcomings. In particular, while such bulbs have improved light output and energy efficiency, they require a ballast and drive circuitry to properly condition and regulate the voltage source.
Many HID underwater lights are of a two-piece construction, having the lamp and drive circuitry in a first, hand-held housing, and a battery power supply in a second housing. Electrical connections between the two housings and the enclosed components are through a cable. While such two-piece construction allows the lamp heads to be of relatively small dimensions, the presence of a connecting cable can be an impediment to use. In addition, the diver must still tether the battery pack in some manner.
It is accordingly a purpose of the present invention to provide a new and improved waterproof flashlight construction utilizing HID lighting in which the light source and power supply are in a single unit.
It is a further purpose of the present invention to provide such a flashlight which is of a compact construction.
Yet a further purpose of the present invention is to provide such a portable flashlight having the capability of convenient battery exchange and replacement.